The described floor covering exhibits a homogeneous structure and relatively high resistance to wear. But such a floor covering is relatively costly, because the process for its manufacture is relatively expensive and the raw materials must first be submitted to a complicated procedure for the production of monochromatic granulates or chips. It is necessary in this case to adhere to a precise dosage of the binding agent and colorant additives. In a development of the manufacturing process it is also possible to combine chips of different colors, that is to say, monochromatic chips in a specific mixing ratio relative to the raw material, in which case the binding agent is applied and plasticized, still further binder components being optionally added, and then, after the addition of all necessary materials, the plasticized binding agent is kneaded into a monochromatic product for roll crushing and reduced in size to form monochromatic chips. Several charges of respectively monochromatic chips are then mixed together in a preset mixing ratio and processed into a floor covering. This manufacturing process consists of several steps and is energy-intensive. The several processing steps of the raw material, particularly the preparation of the product for roll crushing and the size reduction of the same into chips and subsequent melting of the chips to the point where they fuse together result several times in the destruction of the "energy content" of the material. The floor covering described must moreover have a homogeneous gap-free structure, which imposes further restrictions on the process of manufacture.
Known from EP 0479053 is another highly compressed covering material. The highly compacted material is produced by compressing pieces of plastic, in which case it is essential that the material be subjected to a continuous rise in pressure at an elevated temperature. Double flat presses are employed to produce the material described. Suitable as raw materials are pieces of plastic. The final product is supposed to exhibit a homogeneous structure. These demands upon the final material have the consequence that it is necessary to utilize high pressures and temperatures in the manufacturing process, which lie within the melting range of the plastics employed.
Known moreover from DE-PS 35 46 184 is another floor covering made of thermoplastic synthetic materials in which plate-shaped molded pieces made of thermoplastic synthetic materials, especially cuttings, pieces or chips are processed into a homogenous product without gaps. The process for the production of the structure disclosed is expensive like those described above. The shaped pieces must first be sintered at a temperature above approximately 130.degree. C.; at the end of the sintering interval the temperature is increased to about 170.degree. C. to heat the layer of shaped pieces uniformly and permit them to be pressed into a material with a homogeneous gap-free structure.